1. Field of the Invention
The invention concerns a variable-delivery external gear pump comprising a casing, at least one rotatively driven pair of gears comprising two intermeshing spur gears which form with shell surface areas of the casing and axial sealing surface areas a delivery space comprising a low-pressure side connected to a pump inlet port and a high-pressure side connected to a pump outlet port, and a piston, serving to rotatively mount one spur gear of said pair of gears, the piston being shifted relative to the other spur gear of said pair of gears so as to vary the delivery of said pump together with the one spur gear by charging said high-pressure side with fluid against the force of a return element. More particularly, the invention concerns an external gear pump which automatically regulates itself with increasing speed.
2. Description of Related Art
One external gear pump in the field concerned is known from German Patent DE 41 21 074 A1.